在iOS 7中的UINavigationController上推送视图时，如何交叉溶解？

Question

如果我只是调用push方法：

[self.navigationController pushViewController:viewController animated:YES];

然后它使用推动画。如何更改它以使用交叉溶解动画，就像我可以使用模态segue？

Answer 1

您可以使用CATransition中演示的this answer：

CATransition* transition = [CATransition animation];
transition.duration = 0.5;
transition.type = kCATransitionFade;
[self.navigationController.view.layer addAnimation:transition forKey:nil];
[self.navigationController pushViewController:viewController animated:NO];

Answer 2

我使用扩展名来轻松重用：

extension UINavigationController {
    func fadeTo(_ viewController: UIViewController) {
        let transition: CATransition = CATransition()
        transition.duration = 0.3
        transition.type = kCATransitionFade
        view.layer.add(transition, forKey: nil)
        pushViewController(viewController, animated: false)
    }
}

注意动画是如何虚假的;当您将其设置为true时，您仍会看到标准的“推送”动画（从右到左）。

Answer 3

UINavigationControllerDelegate协议有一个方法可以返回一个自定义的UIViewControllerAnimatedTransitioning对象，该对象将控制转换中涉及的两个视图控制器之间的动画。

创建一个Animator类来控制交叉溶解过渡：

class Animator: NSObject, UIViewControllerAnimatedTransitioning {

    let animationDuration = 0.25

    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
        return animationDuration
    }

    func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
        let toVC = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.to)
        toVC?.view.alpha = 0.0
        let fromVC = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.from)
        transitionContext.containerView.addSubview(fromVC!.view)
        transitionContext.containerView.addSubview(toVC!.view)

        UIView.animate(withDuration: animationDuration, animations: {
            toVC?.view.alpha = 1.0
        }) { (completed) in
            fromVC?.view.removeFromSuperview()
            transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
        }
    }
}

并在您的UINavigationControllerDelegate中提供它：

func navigationController(_ navigationController: UINavigationController, animationControllerFor operation: UINavigationControllerOperation, from fromVC: UIViewController, to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? {
    return Animator()
}

这是一个更深入的教程：http://blog.rinatkhanov.me/ios/transitions.html

Answer 4

SWIFT 3 - 截至2018年4月

let transition = CATransition()
transition.duration = 0.5
transition.type = kCATransitionFade
self.navigationController?.view.layer.add(transition, forKey:nil)

Answer 5

您可以像这样设置Push viewcontroller。

        CATransition* transition = [CATransition animation];
        transition.duration = 0.4;
        transition.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
        transition.type = kCATransitionFade;
        [self.navigationController.view.layer addAnimation:transition forKey:@"kCATransition"];
        [self.navigationController pushViewController:readerViewController animated:false];

您可以像这样设置Pop viewcontroller。

         CATransition* transition = [CATransition animation];
         transition.duration = 0.4;
         transition.timingFunction = [CAMediaTimingFunction 
         functionWithName:kCAMediaTimingFunctionEaseOut];
         transition.type = kCATransitionFade;
         [self.navigationController.view.layer addAnimation:transition 
          forKey:@"kCATransition"];
         [self.navigationController popViewControllerAnimated:false];